I am kinda new to all this but I'm thinking of buying my first robot. I like the robobuilder so far, but there is one thing I want to ask. How is the battery? I know it lasts about 15 - 20 minutes on a single charge, but when do you have to replace it? And MOST OF ALL - where can I buy these???

Thank you!

Hello there,

I am kinda new to all this but I'm thinking of buying my first robot. I like the robobuilder so far, but there is one thing I want to ask. How is the battery? I know it lasts about 15 - 20 minutes on a single charge, but when do you have to replace it? And MOST OF ALL - where can I buy these???